Open AccessA Comparison of Five Genetically Distinct Invertases from Saccharomyces
Author(s) -
Ottoleghi Paul
Publication year - 1971
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1971.tb01275.x
Subject(s) - invertase , sucrose , hydrolysis , enzyme , saccharomyces cerevisiae , chemistry , biochemistry , substrate specificity , kinetics , glycoside hydrolase , extracellular , stereochemistry , biology , gene , physics , quantum mechanics
The β‐D‐fructofuranoside fructohydrolases (invertases) of Saccharomyces under the control of the non‐alleic genes SU‐1, SU‐2, SU‐3, SU‐4, and SU‐5 have been examined with respect to the effect of pH on the Michaelis contstants and maximum vlocities of their hydrolysis of sucrose. In every case, the two molecular forms of each invertase (the large extracellular form and the small intracellular form) appeared to be identical as far as the reaction kinetics, but between the different invertases both similarities and differences exist. If quasi‐equilibrium is assumed to be operative, the reaction of all the invrtases fits a model according to which the enzyme‐substrate complexes of all five invertases behave, kinetically, in identical manner. The unsubstrated enzymes, on the other hand, show small but definite differences: SU‐1 and SU‐4 invrtases and SU‐2, SU‐3 and SU‐5 invertases form two groups within which the enzymes respond in essentially identical manner to variations in the environmental pH. SU‐2 invertase can be separated from the second group as it is unique among the five invertases studied in being inhibited by o ‐dianisidine.